Method and apparatus for grinding plane surfaces



June 18, 1946. w. c. SUTTON METHOD AND APPARATUS FOR GRINDING PLANE SURFACES Filed Nov. 4, 1943 4 Sheets-Sheet 1 INVENTOIIQ. gl alfez' (IX attain Atty June 18, 1946.

W. C. SUTTON METHOD AND APPARATUS FOR GRINDING PLANE SURFACES Filed Nov. 4, 1943 4 Sheets-Sheet 2 IN VEN TOR. v

Atty

Waltg'SptfoI: BY

June 18, 1946. w SUTTON 2,402,305

. METHOD AND APPARATUS FOR GRINDING PLANE SURFACES Filed Nov. 4, 1945 4 Sheets-Sheet 3 lzaa IN V EN TOR.

u aliez lfiallon BY 'Augv June 18, 1 946. SUTTO 2,402,305

METHOD AND APPARATUS FOR GRINDING PLANE SURFACES Filed Nov. 4, 1945 4 ShetS-Sh6e1; 4

INVENTOR.

.- f ValterflS'zltton CMa bers.

Patented June 18, 1946 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR GRINDING PLANE SURFACES Walter 0. Sutton, Shaker Heights, 'Ohio, assignor to The S. K. Wellman Company, Cleveland, Ohio, a corporation of Ohio Application November 4, 1943, Serial No. 508,931

20 Claims. 1

This invention relates to a method of and apparatus for grinding discs, rings, and the like fiat'objects, and more particularly to precision mechanism for grinding annular or ring memfor automatically varying the speed of advance of the work during the grinding operation.

Another object of the invention is the provision of feeding mechanism for a grinder that is automatic in its operation but is under manual control.

Another object of the invention is the provision of new and improved means for advancing the work to the grinder member at a relatively fair speed during the initial advance period, and with a greatly retarded speed during the final portion of the grinding operation. I

A further object of, the invention is the provision of feeding mechanism that isunder manual control but that may be set to operate automatically during the grinding period.

A still further objectof the invention is the provision of a new and improved grinder that is simple in construction, effective in operation, positive and accurate in its movement, and that is capable of exactly duplicating its ground p oducts.

Other and further objects and advantages of the invention will appear from the following description, taken in connection with the accompanying drawings in which Fig. 5 is a section on the line 5-5 of Fig. 4:

and

Fig. 6 is a vertical section of one of the valves, shown more or less diagrammatically.

In the construction of high grade precision grinding machinery great accuracy is required in the manufacture of certain parts of the mechanism. In certain products made with such machines tolerances within extremely narrow limits are not uncommon. Such accuracy results in a large percentage of rejects. In the manufacture of certain types of ring or clutch plates having friction faces constructed from powdered metal material, for instance, the tolerances ,must be held within extremely narrow limits, and the plates must be perfectly fiat, parallel and true;

i. e., the'face must be perpendicular'to the axis of the ring.

The present invention seeks to provide a rotary surface grinder apparatus that is so constructed that plates, rings, annular members, and like flat constructions may be efficiently ground to very accurate dimensions, and be so ground as to bealmost perfect duplicates of one another.

Referring now to the drawings, the reference Fig. 1 is a side elevation of the apparatus, with parts in section, parts broken away, and parts omitted for the sake of clearness;

Fig. 2 is a vertical section of the work spindle housing and associated parts, shown on an enlarged scale;

Fig. 3 is a front elevation of the apparatus, with parts in section, parts broken away, and parts omitted for the sake of clearness;

Fig. 4 is a longitudinal vertical section of the grinder mechanism, with parts removed and parts broken away;

character l0 designates the grinding apparatus, Figs. 1 and 2, which comprises a frame H on the upper portion of which is mounted a grinder mechanism l2, 9. motor l3 for. operating the grinder mechanism, feed mechanism It including a work spindle, a motor l5 mounted on the lower portion of the frame for operating the spindle, a. feed stop mechanism IS, a vacuum or chuck plate l1, and an oil pump l8, operated from the motor l3, for supplying a lubricant to diflerent mechanisms and for raising and lowering the chuck.

The grinder mechanism I2 i mounted on the upper portion of the frame II, and comprises a spindle housing I9, Fig. 4, within which is ,1ournaled a horizontal grinder spindle won the front 20. The portion 01' the bore between the bear-' ings, which are spaced apart, forms a lubricant reservoir for oiling the bearings of the spindle 20. These bearings are held in position in the usual manner, as by means of the D11 5.- One for each section of the bearing and one of which is shown in Fig. 4. Since these hearings are well known in the art it is not thought necessary to illustrate or describe the same any further than to state that they are sectional bearings, and

each section has its ends on different radii, so that the bearings are kept well oiled and very accurately journal the spindle 20.

The rear end of the housing I9, Fig. 4, is provided with a cap or packing retainer 25, which is adapted to be rigidly secured to the rear end of the housing I9, as by means of the screws or bolts 26. The grinding spindle 20 is-reduced at what will be termed its outer or rear end, as at 21, to provide a shoulder 28 against which a thrust collar 29 abuts. The thrust collar 29 is clamped in the housing l9 and is loose on the spindle 20.

A pair of lock'nuts 3|, 32 are threaded on the reduced portion 21 adjacent the shoulder 28. The shoulder 28 and nuts 3|, 32 cooperate with the fixed washer 29 to hold the spindle axially. The packing retainer or cap 25 is provided with an axial opening through which the reduced end 21 of the spindle extends, and is counterbored, as at 33, for receiving the nuts 3|, 32. An additional counterbore 34 is provided for receiving a packing 35 for preventing leakage of lubricant along the shaft.

' The outer or rear end of the housing I9 is counterbored, as at 35, and the packing retainer or cap 25 is provided with a reduced inward extension 31, which, when the parts are assembled, forms with the counterbore 36 a peripheral groove 38 in which the thrust collar 29 is held. The forward end of the housing I9 is provided with a packing retainer or plate 39, having an axial opening 4| provided with an inwardly extending flange 42 adapted to retain annular packing members 43 in position against the bearing 22. The annular packing members 43 are mounted on a collar portion 44 on the forward end of the spindle 20.

The end of the spindle 20 forwardly of the collar 44 is slightly reduced, as at 45, and again reduced, as at 46. Mounted on the reduced portion 46 is the grinder member or wheel 2|, having a bushing 41 between it and the reduced portion 45. The grinder member 2| is clamped in position by a pair of clamping members or wheel flanges 48 and 43. The flange 49 is mounted on the reduced portion 45, and bears against the collar 44; and the wheel flange 48 is mounted on the reduced wheel portion 48, and the whole assembly is clamped in position by a nut 5| threaded on the forward end of the wheel spindle 20.

The packing retainer 39 is provided with a flange 52, to which a grinder wheel guard 53 is secured. The wheel guard 53 comprises a peripheral portion 54 rigidly connected to the flange 52, and a side or door portion 55, which extends down over the forward end of the grinder spindle 20 and, with the member 53 and flange 52, constitute a safety and dust shield for the grinder wheel. The door 55 is hinged at 56, and is held in closed position by a latch 51, Fig. 5. This closure or door affords access tov the grinder wheel and associated parts, when desired. A housing 30, Fig. 1, is provided for inclosing the wheel spindle housing l9, and forms a shield therefor and for associated parts, including the pulley 20*- on the reduced end 21 of the spindle 20.

Suitable means are provided for moving the spindle and grinder wheel member 2| longitudinally of its axis, and this construction will now be described. The lower end of the grinder wheel spindle housing i9 is provided with a supporting portion 58, Fig. 5, which has laterally extending flanges 59, 6|. These flanges each have their upper surfaces extending downwardly and outwardly, as at 82, and glbs 83 are provided for engaging these inclined surfaces for forming a guideway for the longitudinally movable grinder wheel spindle 21 and housing l9. 7

Any suitable means may be-provided for moving the housing, together with the spindle 20 and grinder wheel 2|, longitudinally of theiraxes, but in the form of construction selected to illustrate one embodiment of the invention a rack 64, operated by a pinion 65, is employed for this purpose. The rack 64 is rigidly connected to the base 58, and is movable along a slot 64 in the support 54'. The pinion 65, Figs. 4 and 5, is secured on or integral with a shaft 66, to the outer end of which is secured a crank handle 61, Fig. 3. It will thus be seen that by manually rotating the handle 31 in one direction or the other the grinder member 2| may be moved'either toward the right or to the left, as viewed in Fig. 4. This adjusting arrangement permits the grinder member to be moved back and forth when the same is being dressed, as well as for properly adjusting the grinder member relatively to the work that is being held by the chuck H, as will be hereinafter explained.

The grinder spindle 20 has a pulley 20 mounted on its outer or rear end, and this pulley is rotated from the motor l3 through suitable belt means 2|] engaging the pulley 20 and a pulley |3- on the outer or rear end of the armature shaft of the motor |3.. The motor is located a sufficient distance away so that the belt means 20 will be long enough to permit the limited longitudinal movement of the grinder spindle.

Suitable means are provided for holding, adjusting and rotating the work, as well as moving the same toward and from the grinder wheel during the grinding operation. In the form of the apparatus shown, which is by way of example only, the feed mechanism l4 comprises a work spindle housing 68, Fig. 2, within which is rotatably mounted the work spindle 69. The work spindle carries at its upper end the vacuum chuck l1. The spindle 59 is elevated to bring the work into contact with the grinder wheel by hydraulic means, as will hereinafter appear. The lower end of the work spindle 69 is reduced, as at 60. and has keyed thereto a pulley 85 by means of which the spindle is rotated. This pulley is operated from the motor l5 by means of suitable belts 86, Fig. The pulley 85 has a wide belt engaging surface so that the spindle 69 and pulley 85 may be raised and lowered, as will appear hereinafter, without stretching the belts.

The housing 58 is provided with a cylindrical axial opening 10, which extends throughout its length, and the upper end of this housing is reduced and threaded, as at 1|, for engaging the interior threads of the feed stop gear and nut 12, as clearly shown in Fig. 2 of the drawings, The lower end of the work spindle housing 68 has its axial opening '10 reduced, as at 13, for receiving the upper end of a bushing retainer 14. This bushing retainer has a flange 15 on its lower end, which is received in a counterbore 16 in the lower end of the work spindle housing 68, and the bushing retainer 14 is provided with a reduced cylindrical opening in which is secured a bushing or bearing 11 which may be of bronze or any other material suitable for bearings.

The upper end of the bushing 11 is provided with a flange 18 for engaging the upper end of the bushing retainer 14. The bushing 11 is provided on its interior surface with a plurality of oil rings 19 for lubricating the spindle ESQ-four being shown. The bushing retainer II is held in.

being clamped in position by means of screws'83.

The packing retainer 8| has an axial opening provided with a, counterbore on its upper side, within which suitable packing is secured. This packing prevents the loss of lubricating oil from the chamber I8 along the work spindle 69.

Mounted on the upper end of the work spindle 69 is the vacuum chuck, Fig. 2. Suitable means are provided for attaching this chuck in position on the upper end of this spindle, so that the same will properly. function to hold the work during the grinding operation. As shown, the upper end of the spindle is reduced, as at 87, and is screwthreaded for engaging in the threaded opening in a vacuum chuck spindle adapter 88, which is adapted to seat On a shoulder 89 formed on the spindle 69 by the reduced portion 81. The chuck adapter an work spindle 69 are provided with cooperating annular cut-out portions which. when the adapter is seated on the shoulder 89, will form an annular air conduit 98 extending entirely around the reduced portion 81, as will presently appear.

The chuck adapter 88 is provided on'its lower side with an enlarged counterbore I48, which provides a flange projection 58 extending around the spindle 69 but spaced therefrom for receiving the upper end of a feed stop sleeve 88, hereinafter explained.

The adapter 88 is provided on its upper side with a counterbore 9|, within which is seated an annular chuck adapter insert 82, which seats on the upper end of the work spindle.69. The vacuum chuck I! is in the form of an annular plate, adapted to be clamped to the upper side of the chuck adapter 88, as by means of bolts or screws 93 extending through the plate of the chuck I1, and are tapped into a flange '18 extending outw'ardly around the adapter 88. The chuck plate I I is provided with an axial opening, as at 94, which is counterbored below, as at 95, for receiving the upper end of the chuck adapter insert 92,

The chuck plate I! has an annular elevated work rest 96 on its upper face, which extends above the surface of the upper side of the plate, so that the work may be supported entirely thereon without contacting any other portion of the plate. The plate isprovided with an annular recess 91 beneath the elevated work rest 96. A

plurality of apertures I88, arranged in concentricrows, extend from the recess 91 to the upper surface of the work rest 98, through which air may be exhausted for holding the work in position on the rest, as will presently appear.

Suitable means are provided for rigidly clamping the central portion of the vacuum plate in position .on the vacuum chuck spindle adapter and against the adapter insert. As shown, this the screw or bolt IN, and the parts are thus rigidly clampedtogether. In order to further prevent relative rotation of the chuck plate I! and member 98, one or more pins or screws I82 may extend through the headof the member 98,

the chuck plate II, the chuck adapter insert 92,

and be tapped into the vacuum chuck spindle adapter 88. I

Appropriate means are provided for holding the work on the work rest 98 of the vacuum chuck plate I! during the grinding operation. This is done by vacuum. As shown, the upper end of the vacuum chuck spindle adapter 88 is provided with an annular recess I83, which is directly below the recess 91 of the vacuum plate I I, and

a plurality of suitable bores I 84, converging toward their lower ends, are drilled through the chuck spindle adapter from the recess I83 to the annular recess 98, as clearly shown in Fig. 2 of the drawings. The work spindle 89 is provided with an axial bore or conduit I85 that extends throughout its length. The upper end of this bore is provided with a plurality of reduced branch bores I85 which diverge upwardly and are in communication with the air conduit or manifold 98, and as a result of this arrangement when air is exhausted through the conduit I85 it will exhaust the air in the recesses I88 and 91, and through the passages I 88, for holding the work firmly in position on the work rest or support 96. The lower end of the bore I85 is in communication with an exhaust air conduit I86, which in turn is connected with a vacuum line or with the intake of a suitable vacuum pump.

means comprises a vacuum chuck work adapter 98, provided with a cylindrical body portion 99 extending through the axial opening 94 in the chuck plate IT, and into the axial opening in the chuck adapter insert 92. Its upper end is flanged of the pipe of the conduit I88.

to form a, head which extends over the chuck plate I1. This member is provided with an axial opening through which a'screw threadedbolt 'I8I extends, and is tapped in the upper end of the reduced portion 81 of the work spindle. The axial opening through the adapter 98 has its upper end counterbored for receiving the head or The connection'between the lower end of the spindle 69 and the air conduit I 86 will now be described. The lower end of the work spindle 69 is further reduced at I81 to form a shoulder I 88, Figs. 1 and 2. The reduced portion I8! is threaded, and is adapted to engage a threaded recess in a cap member I89. This cap member seats against the shoulder I 88. A plate H8 is positioned on the spindle above the cap member I89, as shown more clearly in Fig. 2 of the drawings. The cap member I89 is provided with an axial opening below the spindle 69, in alinement with the bore I85 of the spindle. The cap member I89 is adapted to be received within a recess III formed in the connector block H2. The upper end of this block seats against the plate H8, and suitable means are provided for resiliently holding the parts in contact for constituting an air-proof joint at this point. The means shown comprises a plurality of bolts 'I I3 extending upwardly through the block member .I I2,'and are threaded into the plate II8. Interposed' between the block and the heads of the bolts are springs I I4. A gasket H5 is inserted between the cap gasket H5, and the bore I85 of the spindle. The

lower end of 't-hebore IIB is counterbored and threaded for receiving the upper threaded end The block II2 may be provided with a threaded opening for receiving a handle member II! for rotating the a block II! for attaching and releasing the same to and from the pipe of the conduit I88, Fig. 2.

The conduit I86 has a flexible conduit II8 connected thereto, so as to accommodate the raising and lowering of the spindle 89 for raising and lowering the chuck and the work thereon, as will presently be described. The conduit H8 is attached to a pipe connection '9, to which may be connected a pressure gauge I2 I, as shown more clearly in Fig. 1 of the drawings. A pipe I22 is attached to the pipe connection H9, and has a three-way valve I23 therein, which may be of the usual or any well known construction. Its descrlption is not thought necessary further than to state that it comprises a valve casing I23 Fig. 6, having a rotary cylinder I23 therein provided with a T-shaped aperture I23" therethrough. The cylinder may be turned to place the conduit I22 in communication with either the conduit I21 or I26.

The valve is operated through the medium of a rod I24, which has its lower end attached to the valve I23 and has a handle I25 at its upper end. By moving the handle either to the right or to the left the valve is operated. Attached to the valve I23 is the conduit I26, to which is connected a conduit I26 leading to a vacuum tank, and which in turn is connected to a vacuum line or to the intake of a vacuum pump. In practice a vacuum tank is interposed between the conduits I26 and I26, and is located in the base of the apparatus. Attached to the three-way va1ve.l 23 is an upwardly extending pipe I 21, which is connected to a pipe I28, and which in turn connects to a three-way valve I29 in communication with a horizontal pipe I28 The valve I29 is similar to the valve I23 described above, and shown'in Fig. 6, and need not be further described.

The valve I29 has the two conduits I28 and I28 connected thereto, and also has an intake port or passage I29. When in one position the conduits I 28 and I28 are in communication and the port or nozzle I 29 is closed, and when in another position the conduit I28 and port or noz zle I29 are in communication and the conduit I28 is closed.

When it is desired to secure the work to be ground to the chuck,'the handle I25 is operated to turn the valve I23 to close the conduit I21, Fig. 6, and to place the conduit I26 in communication with the conduit I22 and the hose Qr conduit I I8, and the suction in the conduits I26 and I26 will cause suction in the chuck I1 to firmly clamp the work to the chuck. The work is released from the chuck by turning the handle I25 to close the suction conduit I26, and to place the conduits H8 and I21 in communication with each other. The valve I29 is now turned to open the conduit I21 to the atmosphere through the port I29, and e):- ternal air will enter the conduit I21 and flow through the conduits H8 and I to relieve the vacuum in'the chuck for releasing the work.

' If desired, means may be provided for employing compressed air for relieving the vacuum in the chuck for releasing the work, and at the same time blow any foreign matter, such as the liquid coolant or ground fragments, from the suction passages of the chuck. As shown, the conduit I20 is extended to a conduit I3I having a valve I32 therein. The conduit I9I is in communication with a source of compressed air. The valve I29 may be turned to open the passage I28 and close the port I29. When in this position, if the valve I32 be opened and the valve I23 be moved to place the conduits I22 and I21 in communication,

compressed air will now pass throu he o duits I3I and I21, valve I23, conduits H8 and I05, to the chuck for promptly relieving the work and for cleaning the vacuumpassages therein.

be described.

A pipe connection I30, having a valve I33 therein, may be provided between the conduits I3I and I26, so that by turning the valves I29 and I23 to close the conduits I28 and I26, respectively, and then open the valves I33 and I32, compressed air may be discharged through the conduit I26 into the vacuum tank for removing water or foreign matter therefrom. During the normal operation of the apparatus the valve I33 remains closed.

It will thus be seen that when it is desired to secure the work to be ground, such as a disc or ring, on the vacuum chuck I1 the operator moves the handle I25 to operate the three-way valve I23 to close the passage through the pipe I21 and simultaneously open the passage I26 to the source of vacuum for exhausting the air from the chuck through the conduit I06 and bore I05, as will be apparent from an inspection of Figs. 1 and 2.

When it is desired to release the work from the chuck the handle I25 is moved to operate the three-way valve I23 forclosing the conduit I 26 and opening the passage through the pipe I21 to the air valve I29, if the same be open. If the valve I29 is open to the conduit and to the atmosphere, the air will pass through the passage I29, through the passage I21, conduit I06, and bore I05, and through the chuck I1 for releasing the work thereon.

If however, the valve I29 is turned so that the port I29 is closed and the conduit I28 and valve I32 open, then compressed air will be admitted and will promptly relieve the suction at the chuck, and simultaneously blow away any foreign matter contained in the air passages of the chuck.

The mechanism for feeding the work or advancing the same to the grinder wheel will now This mechanism comprises the work spindle 69, the feed stop sleeve 00 for limiting the upward movement of the work spindle which carries the chuck, together with means I35 for vertically adjusting the feed stop sleeve. The spindle 69 is so constructed that it functions as a hydraulic plunger or piston for raising and lowering the chuck secured to the upper end thereof. As shown in Fig. 2, the upper portion of the spindle below the reduced portion 91 i cylindrical, as at I36, and is adapted to slide upwardly and downwardly through the feed stop sleeve 80, and the two function as piston and cylinder.

The lower end of the feed stop sleeve has an annular internal bevel to form an annular shoulder I31 for engaging a corresponding inclined surface I30 on an enlargement I39 at the lower end of the cylindrical portion I36 of the spindle 69. The shoulder I31, engaging the inclined surface I38, limits the upward movement of the spindle, and consequently determine the amount of material to be ground from the work that is being operated upon. By adjusting the feed stop sleeve upwardly more material will be ground from the work, and by adjusting it downwardly a correspondingly smaller amount will be ground from the work carried by the chuck I1. Since the stop engages the inclined surface I38 on the work spindle throughout fully 360, the limit of upward movement of the spindle is extremely accurate becausethere is no tilting or rocking of the sleeve 80, and as a result the amount of material removed from the work, or rather the thickness of the ground or finished article, will be held to within very narrow limits, and the ground surface will be true.

Suitable means are Provided for M adjustably raising and lowering the feed stop sleeve 80. As

shown, the upper end of the spindle housing 68 is reduced, as at I, and a feed stop gear 12 is threaded-thereon. The upper end of the feed other the sleeve may be raised or lowered, thereby raisin and lowering the stop I31'for limiting the upward movement of the spindle 69. The flange I44 is positioned a suflicient distance above the upper end of the spindle housing to provide clearance for the movement of the sleeve 80, and also forms a reservoir I64 for receiving oil accumulated abovethe sleeve 80, as will presently be described. The sleeve 88 has a plurality of annular oil grooves I88, ten being shown, which extend around the interior thereof for retaining oil for lubricating the spindle during its rotation.

It is necessary, in precision grinding, that means be provided for accurately adjusting the sleeve 80 for properly positioning the annular stop shoulder I31. As shown, a worm I41, Fig. 3, is provided for meshing with the teeth I48 of the gear 12 for rotating the same. The worm I41 operates in a casing I49,'and is provided with a shaft II extending through a bearing block I49, rigidly mounted in the casing I49. The worm abuts the block, which prevents its outer endwise movement.- An adjusting wheel I 52,.having a handle I53, is attached to the outer end of the shaft I5I for rotating the same. The hub of the wheel abuts the end of the casing I 49 and prevents rearward movement of the worm I41. Micrometer graduations I54 on the hub of the wheel I52 and casing I43 areprovided for indicating the accurate adjustment.

By means of this arrangement extremely accurate adjustments may be obtained by rotating the worm I41. The worm I41 and easin I48 are carried by a plate I 56, which is pivoted, as at I51, Fig. 3, to a suitable support I58 rigidly mountedon the spindle housing 68. .The casing I49 is cut away, as at I59, Fig. 2, for providing clearance for the teeth I48 of the gear 12. The

worm is held in engagement with the teeth of the feed stop gear 12 by any suitable means, as by a button member I 6I, which is adapted, when turned in one position, to pass through a slot I62 in the plate I56, and to be turned crosswise of the slot, as shown in Fig. 3, for holding the plate I56 in the position shown in Fig. 2. The button member I6I is preferably screw-threaded into the support I58, so that when it is turned it will hold the worm firmly in mesh with the teeth of the feed stop gear. By releasing the plate I56 the worm may be disengaged from the gear teeth. It will be seen that by turning'the handle I53 the feed stop gear 12 will be rotated for raising and lowering the sleeve 60, and with it the stop shoulder I31 for limiting the upward movement of the spindle 69. A grease nipple I48 is provided on the casing I49 for introducing lubricant to the bearing in the'block'l48.

Hydraulic means are provided for elevating the spindle 69, and withit the chuck and work thereon. In the form of device selected to illustrate one embodiment of the invention, the hydraulic fluid employed is oil, which is also used for lubrieating the parts. As shown more clearly in Fig.

. 10 2, the spindle 69 is provided with a collar I63 integral with and below the enlargement I39, and which is of slightly larger diameter than the enlargement I39. The spindle is thensharply reduced, as at I64, immediately below the enlargement I63 and within the space between the sleeve 80 and the upper end of the bushing retainer 14.

This space constitutes a cylinder or chamber 10 for containing a hydraulic fluid which, in this instance, is oil. Below the reduced portion I64 the spindle is further materially reduced, as at I64, and the reduced portion I64" extends through the bushin 11 below the chamber 10.

The operating fluid, such a lubricating oil, is introduced into the lower end of this chamber through a flexible conduit I65, Fig. 1, and, due to the reduction in diameter of the lower end of the spindle, will force the spindle upwardly, thus elevating. the chuck. The discharge for the hy-' draulic fluid is back through the conduit I65 to a three-way valve I85, as will now be described.

The circulation of lubricant to the hydraulic cylinder and to the different bearings may be traced as follows: The lubricant is contained in a tank I61, Fig. 1, and is pumped therefrom through the conduits I8 and I8 by the pump I8, and discharged into a conduit I69 through the discharge pipe I68. A pressure relief valve I1I is provided in aby-pass I12, so that when the pressure in the conduit I68 rises above a predetermined amount a portion or all of the liquid will be discharged into the pipe I12" through the pressure relief valve, which in turn discharges into the intake of the pump or back to the oil reservoir I61. Th liquid passes along the conduit I69 and is divided, and a portion passes upwardly through a conduit I13 into. the oil chamber I14 in the spindle housing I9, and from, thence i discharged into a return conduit I15 through a .T-connection I16 into a conduit I11 which passes back to the oil tank I61.

A conduit I18, branching from the conduit I11, carriesa portion of the return oil to the lower part of a filter I19, and after passing'through the filter is conducted by a passage I8I back to the oil tank. A pressurev gauge I82 is provided in the conduit I15 for indicating the pressure contained within the reservoir I14. '11 needle valve I83 in the pipe I15, posterior to the gauge I82, is provided for controlling the pressure in the reservoir I14 for insuring proper lubrication of the grinder spindle bearings.

The-remainder 0f the oil passing along the conduit I68 is conducted over to a three-way through. By controlling the flow of liquid or lubricant through the passage I84 the rapidity with which the spindle I64 will descend may be controlled independently of the three-way valve I 85. By turning the handle I86 to a predetermined position, the passage I69 is closed and the conduit I i placed in communication with the conduit I84 through which the oil'from thecylinder 18 is discharged, and the weight of the cylinder causes it to descend.

In grinding accurate work it is desirable that the rateof speed of the feed be reduced as the grinding operation nears its completion, so thatthe ground faces of the finished product will be accurate and have a maximum smoothness. This is partially accomplished by reason of the fact that the portion I6 4 of the spindle is mu h smaller than the portion I64, so that as the spindle is forced upwardly by the oil a relatively larger portion of the smaller diameter of the spindle will occupy the space within the chamber 19, and consequently more oil will be required to move the spindle a predetermined distance. This results in a gradual lessening of the rate of speed of the feed.

Suitable means are also employed for providing a dash pot action of the upward movement of the spindle, so that the final upward feeding movement of the work spindle is very greatly retarded as it reaches its upper limit. The mechanism for accomplishing this will now be described. A feed stop dash pot cylinder I89, which is in the form of a metal band, is provided which extends about the enlarged portion I39, tightly engages the same, and rests on the ledge formed by the enlarged portion I39, as shown more clearly in Fig. 2 of the drawings. This band extends above the beveled or inclined edge I38, and when this inclined edge is in contact with the lower end of the feed stop sleeve 88 the upper edge of the band I89 will be received in a rabbet I9I extending about the lower end of the feed stop sleeve 80, and which, with the inner surface of the work spindle housing, forms an annular groove for receiving the upper edge of the band I89. The inclined or beveled face I38 of the enlargement I39 is provided with radial grooves I92, and the inner surface of the feed stop sleeve 80 is provided with a p i y f il grooves on its interior surface, ten being shown, for lubricating the cylindrical portion I36, which constitutes the upper journal for the spindle 69.

When the spindle 69 is elevated and nears the upper limit of its movement, the band I89 enters the rabbet or groove I9I and traps the lubricant contained in the upper portion of this band, and the further upward movement of the spindle forces some of this oil upwardly between the cylindrical portion of the spindle I36 and the sleeve 80. This will materially retard the upward movement of the spindle, and the, oil will be finally forced into the space or counterbore I46 above the sleeve 80. This arrangement not only retards the upward movement of. the spindle during its flna1 movement, but will also thoroughly lubricate the spindle within this sleeve by what may be termed a force feed.

Suitable provision is made for returning the oil collected in the space or counterbore 40 back to the main oil reservoir I61. The sleeve is provided with one or more downwardly extending passages I93, which permits the oil to flow down pan I98, surrounding the chuck, is provided for collecting the coolant discharged across the work. This pan is provided with a discharge conduit I89 for removing the liquid from the pan I98. A shield or skirt 200, secured to the flange and extending around the same, is provided for protecting the parts against the drippings of coolant from the suction chuck I1, and directs the coolant into the pan I98. Other shields may be provided for protection against moving parts of the mechanism, such as the shield 203, which forms a housing for the pulley 85.

Under some conditions it is desirable that air b employed as the coolant and as a means for removing dust and other fine material removed from the work by the grinder. An exhaust conduit is provided for this purpose. This conduit is bifurcated, the furcations 29I and 202 being shown in Fig. 5, and these iurcations are positioned at opposite sides of the grinder. Atmospheric air will be caused to flow across the work and into this exhaust conduit which carries the dust away from the machine.

In the operation of the grinder, starting with the chuck in its lowered position, the work is placed in proper position on the vacuum chuck and the valve I23 opened to secure the work to the chuck by suction. The motors I3 and I5 ar set in operation for rotating the grinder and the chuck and the oil pump for lubricating certain of the parts, including the grinder spindle which rotates at a higher speed than the work spindle.

The valve I85 is opened for applying oil under pressure to the work spindle 69 for advancing the into the space or reservoir I64 formed between the upper end of the work spindle housing 68 and th flange I of the sleeve. A bore I94, ex-

tending downwardly in the work spindle housing I '68 and outwardly to the surface of the housing,

work to the grinder. As the spindle 69 rises its speed is reduced, and when near its upper limit oil trapped by the band I89, operating as a dashpot, materially reduces the final advance movement of the spindle so that great accuracy in grinding is obtained, and the ground face of the work is smooth and true. Some of the trapped oil is forced upwardly between the cylindrical portion I36 of the spindle 69 and the sleeve 80, and lubricates the bearing at this point. When the inclined surface I38 engages the sleeve stop the valve I23 is turned to permit the escape of oil from the space 10 for permitting the spindle 89 to lower, after which the valve I23 is operated to shut off the vacuum connection to the chuck and connect the chuck to th atmospheric air orifice I29 to release the work from the chuck. If necessary, the valve I29 may be operated to blow compressed air into the chuck to remove the work, thus completing the cycle.

The constructionshown is designed to grind annular plates or rings having an axial opening of a diameter but slightly greater than the head of the adapter 98, so that this head will centrally turning the wheel I52.

After the machine has been in operation for some time, the grinder wheel 2| will become worn and reduced in diameter. Since the adjustment obtainable by means of the nut 12 is of rather limited extent, provision has been made to pro-.

vide a greater vertical movement of the spindle as the grinder wheel 2| becomes smaller in use. As is shown in Figs. 2 and 3, the feed mechanism I4 is mounted for vertical movement as a spindle, means for raising and lowering said feed. stop sleeve, the lower end of said sleeve coopermove the grinder mechanism vertically. Extending downwardly from the flange 2I2 is a vertical member 2l6 carrying a horizontal member 211 which forms the support for the motor l5.

When the grinder wheel 2| becomes worn to such an extent that the adjustment provided by the nut 12 is insufllcient to raise the work and to engage therewith, the nuts 2 on the gibs 208 and 200 are loosened slightly and the whole grinder assembly moved vertically by tuming the adjustment bolt 2, after which the gibs are again clamped in place.

While the levers or handles I25 and I86 are shown separated some distance apart, in practice they are coaxial, and the handles may be of such lengths that they may both be grasped in the hand and moved together, if desired.

-It is thought from the foregoing, taken in connection with the accompanying drawings, that the construction and operation of my device will be apparent to those skilled in the art, and that changes in size, shape, proportion and detail may be made without departing from the spirit and scope of the appended claims.

I claim as my invention 1. In a grinding apparatus, a chuck, a grinder member, suction means for holding work to be ground securely against said chuck, means for rotating said chuck, means for rotating said grinder member, hydraulic means for advancing said chuck toward said grinder member for grinding said work, stop means comprising an adjustable sliding member forming an adjustable shoulder and means rigid with said hydraulic means for'contacting said shoulder for limiting the movement of said chuck toward the grinder.

2. In a ring grinder, a chuck, means for rotating said chuck, hydraulic means for moving said chuck longitudinally of its axis a rigid shoulder on said last named means, an adjustable stop for abutting said shoulder for limiting such longi- 14'' duced intermediate portion and a further reduced lower portion, an annular shoulder portion between said upper and intermediate portions, a feed stop sleeve slidably mounted in the upper end of the spindle housing and constituting a hydraulic cylinder for the piston portion of said ating with said shoulder for limiting the upper movement of said spindle, and a chuck for holding the work to be ground on the upper end of said spindle.

5. In a rotary surface grinder, a rotary grinder member, a horizontal spindle for the same, means for adjusting said spindle along its axis, means for rotating said spindle, a vertical work spindle,

means for rotating the same, a housing for said i work spindle, a stop sleeve slidable in the upper end of said housing, said work spindle having an upper cylindrical portion .iournaled at its upper end in said sleeveand slidable therethrough, the lower end of said sleeve cooperating with an enlargement on said work spindle for limiting its upper movement, means closing the lower end of the work spindle housing and constituting a bearing for the lower end of said work spindle and forming with said sleeve a liquid reservoir, the intermediate portion of said spindle within said reservoir being reduced and its lower end being further reduced and extending into said reservoir whereby when a liquid under pressure is forced into said reservoir the work spindle will be forced upwardly at a relatively high speed during its initial movement but at a greatly reduced speed as it nears its upper limit of movement, means on the upper end of said spindle for holding work to be ground, and means for forcing a liquid under pressure into said reservoir for elevating said work spindle for feeding said work to said grinder member.

6. In a rotary grinder apparatus, a grinder spindle, a grinder wheel on said spindle, a work tudinal movement of said chuck, a grinder member, means for rotating the same, suction means for holding work to be ground firmly against said chuck, means for moving said grinder member in the path of said chuck for grinding said work.

3. In a grinding apparatus, a work spindle, a

housing for the same, a chuck carried by theupper end portion of said spindle and adapted to support work to be ground, suction means for holding said work in position on said chuck, a

rinder member, means for moving said grinder for adjusting the position of said feed stop sleeve.

4. In a grinding mechanism, a work spindle,a

housing for the spindle,. hydraulic means for raising and lowering said spindle, said spindle having an upper cylindrical piston portion, a respindle extending at right angles to said grinder spindle, a chuck for holding work to be ground on the upper end of said work spindle, means for rotating both'of said spindles, hydraulic means including a piston member rigid with said work spindle for moving said work spindle to bring said work into contact with said grinder wheel, and means for causing the-advancement of said work toward said grinder wheel at a slower rate of speed as said wheel nears the limit of its grinding operation, and suction means comprising 'conduits extending longitudinally of said work spindle for holding work on said chuck.

, 7. In a ring grinder, a chuck, a grinder member, suction mean for holding work to be ground 8. In a device of the class described, a vacuum chuck for holding work to be ground, a rotating spindle, a chuck plate having an annular recess on its under face mounted on said spindle and rotatable therewith, an annular raised portion on it upper face provided with apertures in communication with said recess for supporting work to be operated upon, means for raising and lowering said spindle, and means including a passage extending longitudinally through said spindle for exhausting air from said recess for holding work on saidchuck by air pressure.

9. In a fiat surface grinder, a grinder wheel, a housing therefor, a grinder spindle for said wheel,

said wheel spindle journaled in said housing,

means for rotating said spindle, a work spindle extending at right angles to said grinder spindle, a housing for said work spindle, an elongated bearing for one end of said work spindle and having an annular shoulder thereon, an enlargement on said work spindle for engaging sai shoulder for limiting the longitudinal movement of the work spindle toward the grinder wheel spindle, a chuck carried by the end of said work spindle ad- Jacent to said grinder wheel for holding work to be ground, means for rotating the work spindle, means including a worm gear for adjusting said stop shoulder'along said work spindle for arresting the advance of said work spindle toward the grinder wheel during the grinding operation, means for advancing said work spindle toward aid wheel, and means for rotating said chuck beneath said grinder wheel.

10. In a grinding apparatus, a chuck, a grinder member, suction means for holding work to be ground securely against said chuck, means for rotating said chuck, means for rotating said grinder member, hydraulic means for advancing said chuck toward said grinder member for grindingsaid work, an annular shoulder for limiting the advance movement of said chuck, and manually operated means for controlling the speed of advance and return of said chuck. I

11. In a grinder device, a rotating grinder member, a chuck member for holding work to be ground rotating about an axi at an angle to that of said grinder member, means for moving said members relatively toward each other for grinding said work, said chuck comprising a work rest having air passages therein, means for conducting air from said chuck through said passages for holding work on said rest, and manually con-' trolled means for admitting atmospheric air to said passages or for admitting compressed air to said passages for releasing said work.

12. In a grinding apparatus, a-work spindle, a work spindle housing for said spindle, said spindle having an upper cylindrical piston portion, a stop sleeve surrounding said piston portion and telescoping into the upper end of said housin and forming a bearing for said piston portion, an enlargement on said piston portion for engaging said-stop sleeve for limiting the upward movement of said spindle, a chuck mounted on the upper end of said spindle, a feed stop ear threaded on the upper end of said housing and surrounding said housing, means for rigidly concry, a worm engaging said gear, a casing for said worm, a shaft for said worm Journaled in said casing, a hand wheel having a hub engaging said housing for turning said worm for rotating said nut for adjusting the height of said sleeve, the adjacent surfaces of said hub and easing having micrometer graduations thereon for accurately adjusting the position of said sleeve, and means whereby said worm and gear teeth may be disengaged for adjusting said nut manually.

14. In a grinding apparatus having a longitudinally movable work spindle provided with an enlargement, a chuck carried by said spindle, a housing for said spindle, a stop sleeve for enga ing said enlargement for limiting the longitudinal movement of said spindle in one direction through said sleeve, means including micrometer mechanism for accurately adjusting the position of said stop sleeve, and hydraulic means for moving said chuck and spindle longitudinally of the axis of said spindle.

15. In a grinding apparatus, a grinder wheel,

a grinder spindle for rotating said wheel, a spindle housing surroundin said spindle and providing a chamber for containing lubricating oil surrounding said spindle, a work spindle, a work spindle housing surrounding said work spindle, said last-named housing forming a chamber for containing lubricating oil surrounding said work spindle, said work spindle having an enlargement constituting a piston in said last named chamber a chuck on the upper end .of said spindle, and means for forcing the lubricating oil into said piston and said housings for lubricating said spindles and for moving said chuck toward said grinder wheel.

16. In a grinding apparatus, a grinder wheel, a

grinder spindle for rotating said wheel, a spindle meeting said gear to said stop sleeve, a worm enhousing surrounding said spindle and providing a chamber for containing lubricating oil surrounding said spindle, a work spindle, a work spindle housing surrounding said work spindle, said last-named housing forming a chamber for containing lubricating oil surrounding said work spindle, an enlargement on said work spindle for forming a piston in the chamber surrounding said work spindle a chuck on the upper end of said spindle, an oil reservoir for containing a lubricant for said spindles, means including a pump for forcing said lubricating oil into said chambers for lubricating said spindles and formoving said chuck toward said grinder wheel, a filter, conduits for returning said oil from said spindles to said reservoir, and branch conduits for shunting a portion of the returning on through said filter.

17. In a grinding apparatus, a chuck, a spindle for said chuck a grinder member, suction means for holding work to be ground securely against said chuck, means for rotating said grinder member, means for moving said grinder member transversely to said spindle hydraulic means including a piston on said spindle for advancing said chuck longitudinally of its axis toward said rinder member for grinding said work, means for discharging a liquid coolant onto the face of said work during the grinding operation, and means for collecting said liquid coolant and for conducting the same from the apparatus.

18. In a grinding apparatus, a chuck, a spindle therefor, a grinder member, a. spindle therefor, suction means for holding work to be ground securely against said chuck, means for rotating said chuck and its spindle, means for rotating said grinder member and-its spindle, hydraulic means 17 comprising lubricating oil for advancing said chuck toward said grinder member for grinding said work, means for utilizing said oil for lubricat-' ing said spindles and means for exhausting air across said work during the grinding operation for removing the dry dust material from said grinding apparatus.

19. In a grinding apparatus, a. work spindle, a. housing therefor, said housing having an enlarged axial bore, a stop sleeve slidable in the upper end of said housing, a feed stop gear threaded on the upper end of said housing and rigidly connected to said sleeve, means for rotating said gear for raising and lowering said stop sleeve, a work spindle extending through said sleeve and hous- 1 ing and having an upper cylindrical portion forming a close lit in said sleeve, said'sleeve having oil grooves surrounding said cylindrical portion for holding oil for lubricating th latter, a. chuck adapter secured to said' spindle and having a' downwardly extending flange p rtion telescoping over the upper end of said sleeve and forming with said sleeve and spindle an'oil chamber, a chuck secured to said adapter, the lower end of said sleeve having an external rabbet, an enlarged projection on the spindle adapted to engage said sleeve for limiting the upward movement of said spindle, said enlargement having a reduced portion forming an annular ledge, an annular band seated on saidledge, said spindle having internal oil grooves for the lower end of said spindle, means including an oil reservoir and a pump for forcing oil from said oil reservoir into said work spindle housing between said sleeves for lubricating the lower bearing formed by th lower leeve and for elevating said spindle for causing said band to enter said rabbet for trapping oil between said cylindrical and enlarged portions on saidspindle for causing oil to flow upward between said cylindrical portion and first-named sleeve into said chamber for lubricating said work spindle, and conduits for returning said oil back to said reservoir.

20. In a grinder device, a grinder member, a

chuck member for holding work to be ground rotating about an axisv at an angle to that of said grinder member, a piston member for advancing said chuck to and from said grinder member,

means for rigidly connecting said chuck to said piston member, means for holding a work piece to said chuck by suction, a rigid shoulder on said piston, an adjustable stop for positively engaging said shoulder for limiting the upward movementof said pistonand chuck, and means for causing said chuck-to move at a greatly reduced speed as, it nears the limit of the movement toward said I grinder.

WALTER c. SUTTON. 

